Power supply failure alarm circuit

This is very useful circuit for you.Because through this circuit we will be able to know about a power failure.Here We have done some modification,its nothing but this circuit doesnt want an extra power supply for the alarm circuit.Because after the power failure alarm circuit doesnt operate with out power,But here we have attached a capacitor so through that after the power failure this capacitor can operate the alarm circuit.After giving 5V to 15V power.Then tune VR1 till alarm goes on position to off position